It’s slower population growth than in the past, but earlier, too.
In earlier years we’ve had cicada killer wasps — cicada hawks, in some parlance — as early as July 7. Rains fell all spring in 2010, which discouraged the emergence of cicadas and their predators. First certified sighting in our backyard did not occur until July 18.
Cicada Killer, with cicada - photo by Ronald F. Billings, Texas Forest Service, Bugwood.org, via University of Delaware Cooperative Extension
We had modified a planter, and that may have killed some of the larvae. Generally 2010 was a slow year for the large wasps. My guess is that they were less active locally because the ground remained wet through July and into August. I still get e-mails asking about how to get rid of them, and I still recommend watering the spots you want them to leave. The females sting and paralyze a cicada, then plant that cicada in a tunnel underground with one wasp egg. The young wasp hatches and feeds on the cicada, emerging usually the next summer to carry on the cycle (in a long summer, there may be a couple of hatchings, I imagine). Females do not like to tunnel in wet ground, partly because it collapses on them, and I suspect wet ground is conducive to fungi and other pests that kill the eggs or hatchlings. Our wet weather kept them away last year.
I waited to say anything this year because I wanted more, but we saw the first cicada killer wasps this year on June 27, 2011, the earliest date we recorded here. I had hoped to get a good photo, but that hasn’t happened yet.
Down at Colorado Bend State Park, the cicada killers greeted our arrival, much to the panic of the little kids in the campsite next door. They were happy to learn the wasps don’t aim to sting them, and the kids actually watched them at work. One of the wasps reminded me of just how much they like dry ground — she kept tunneling into the fire pit, unused now because of the fire bans that cover 252 of Texas’s 254 counties. Covering the holes, putting objects over the holes, nothing could dissuade her from using that site. I hope for the sake of the larvae that they hatch soon, and get out, before someone builds a fire in the pit. Some of the cicadas in that area hit 110 decibels at least, and they badly need the discipline of a force of cicada killers, if you ask me.
Prowling the yard this morning I found two more emergence holes. The wasps leave a smaller hole than the cicadas, so I’m pretty sure they are back in force.
Nature, red in tooth and claw, the poets say. Or in this case, moist in sting.
It’s summer. By the weather, it’s late summer. Hello, cicada killers, Sphecius speciosa.
Earlier at Millard Fillmore’s Bathtub:
- Most popular cicada-killer post, from 2007: “Cicadas, cicada-killers are back!”
- Photo of our local guys, from their 2008 campaign (some irony: The photo was taken on the lip of the now-removed termite-enabling planter).
- “Cicada hawks a month early – another sign of climate change?” (lots of variation with the weather; need more data)
- Cicada killer on a rose, photo from 2009
- First sighting of 2010
More:
- Good post on the cicadas the cicada killers kill, at Bug Girl
- Prof. Chuck Holliday’s cicada killer page, from Lafayette University (sorta gives new potential meaning to the phrase, “Lafayette, we are here!”)
- Several different species in the Americas; here’s a key to tell them apart
- Texas A&M entry in their field guide to insects
Posted by Ed Darrell 
Millard Fillmore's Bathtub 